1. Field of the Invention
This invention relates to new quinazolines, their preparation and use as bactericides and animal growth promotants as well as addditives to improve feed efficiencies in animals.
2. Description of the Prior Art
Aside from the well known ability of certain antibiotics to increase growth and to improve the feed efficiency when used in the rearing of economic animals such as chickens and hogs, various patents and publications claim similar properties for other types of organic compounds. Often, when the latter are employed in tests where the animals are maintained at a high nutritional level under optimum conditions such as actually practiced in animal husbandry in the United States, they fail to continue to show any substantial growth promotion activity or improvement in feed efficiency.
Nitrofuran quinazolines bearing a substituted phenyl group in the 4-position of the quinazoline such as found in the prior art had the nitrofuran group directly attached to the quinazoline. These compounds shows some activity against Streptococcus faecalis, but gave only little growth promotion in some experiments and none in others. These compounds did not demonstrate any improvement in feed efficiency. One of these compounds was the product of Example III in U.S. Pat. No. 3,542,784 -- Burch, 2-(5-nitro-2-furyl)-4-(p-hydroxyanilino)quinazoline. Further, it was observed that another compound of the prior art, quinazoline 1,4-dioxide showed little growth promotion and improvement of the feed efficiency in tests with animals reared under optimum conditions.
There is a definite need for organic compounds which will provide increased growth and improved feed efficiency when used in the rearing of economic animals.